/* Copyright  (c) 2002 Graz University of Technology. All rights reserved.
 *
 * Redistribution and use in  source and binary forms, with or without 
 * modification, are permitted  provided that the following conditions are met:
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 * 1. Redistributions of  source code must retain the above copyright notice,
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 *
 * 2. Redistributions in  binary form must reproduce the above copyright notice,
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 *    and/or other materials provided with the distribution.
 *  
 * 3. The end-user documentation included with the redistribution, if any, must
 *    include the following acknowledgment:
 * 
 *    "This product includes software developed by IAIK of Graz University of
 *     Technology."
 * 
 *    Alternately, this acknowledgment may appear in the software itself, if 
 *    and wherever such third-party acknowledgments normally appear.
 *  
 * 4. The names "Graz University of Technology" and "IAIK of Graz University of
 *    Technology" must not be used to endorse or promote products derived from 
 *    this software without prior written permission.
 *  
 * 5. Products derived from this software may not be called 
 *    "IAIK PKCS Wrapper", nor may "IAIK" appear in their name, without prior 
 *    written permission of Graz University of Technology.
 *  
 *  THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESSED OR IMPLIED
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package iaik.pkcs.pkcs11.objects;

import iaik.pkcs.pkcs11.Session;
import iaik.pkcs.pkcs11.TokenException;
import iaik.pkcs.pkcs11.wrapper.Constants;
import iaik.pkcs.pkcs11.wrapper.PKCS11Exception;



/**
 * An object of this class represents domain parameters as defined by PKCS#11
 * 2.11.
 * Domain parameters are of a specific type: DSA, DH or X9_42_DH.
 * If an application needs to use vendor-defined domain parameters, it must
 * set a VendorDefinedDomainParametersBuilder using the
 * setVendorDefinedDomainParametersBuilder method.
 *
 * @author Karl Scheibelhofer
 * @version 1.0
 * @invariants (keyType_ <> null)
 *             and (local_ <> null)
 */
public class DomainParameters extends Storage {

  /**
   * If an application uses vendor defined DomainParameters, it must implement
   * this interface and install such an object handler using
   * setVendorDefinedDomainParametersBuilder.
   *
   * @author Karl Scheibelhofer
   * @version 1.0
   * @invariants
   */
  public interface VendorDefinedDomainParametersBuilder {

    /**
     * This method should instanciate an Object of this class or of any
     * sub-class. It can use the given handles and PKCS#11 module to retrieve
     * attributes of the PKCS#11 object from the token.
     *
     * @param session The session to use for reading attributes.
     *                This session must have the appropriate rights; i.e.
     *                it must be a user-session, if it is a private object.
     * @param objectHandle The object handle as given from the PKCS#111 module.
     * @return The object representing the PKCS#11 object.
     *         The returned object can be casted to the
     *         according sub-class.
     * @exception PKCS11Exception If getting the attributes failed.
     * @preconditions (session <> null)
     * @postconditions (result <> null) 
     */
    public Object build(Session session, long objectHandle) throws PKCS11Exception;

  }

  /**
   * The currently set vendor defined DomainParameters builder, or null.
   */
  protected static VendorDefinedDomainParametersBuilder vendorDomainParametersBuilder_;

  /**
   * The type of this key. Its value is one of KeyType, or one that has a
   * bigger value than VENDOR_DEFINED.
   */
  protected KeyTypeAttribute keyType_;

  /**
   * True, if this key was created (generated or copiedfrom a different key) on
   * the token.
   */
  protected BooleanAttribute local_;

  /**
   * The default constructor. An application uses this constructor to instanciate
   * a key that serves as a template. It may also be useful for working with
   * vendor-defined domain parameters.
   *
   * @preconditions
   * @postconditions
   */
  public DomainParameters() {
    super();
    objectClass_.setLongValue(ObjectClass.DOMAIN_PARAMETERS);
  }

  /**
   * Called by sub-classes to create an instance of PKCS#11 domain parameters.
   *
   * @param session The session to use for reading attributes.
   *                This session must have the appropriate rights; i.e.
   *                it must be a user-session, if it is a private object.
   * @param objectHandle The object handle as given from the PKCS#111 module.
   * @exception TokenException If getting the attributes failed.
   * @preconditions (session <> null)
   * @postconditions
   */
  protected DomainParameters(Session session, long objectHandle)
      throws TokenException
  {
    super(session, objectHandle);
    objectClass_.setLongValue(ObjectClass.DOMAIN_PARAMETERS);
  }

  /**
   * Set a vendor-defined DomainParameters builder that should be called to
   * create an instance of vendor-defined PKCS#11 domain parameters; i.e.
   * an instance of a vendor defined sub-class of this class.
   *
   * @param builder The vendor-defined DomainParameters builder. Null to clear
   *                any previously installed vendor-defined builder.
   * @preconditions
   * @postconditions
   */
  public static void setVendorDefinedDomainParametersBuilder(VendorDefinedDomainParametersBuilder builder) {
    vendorDomainParametersBuilder_ = builder;
  }

  /**
   * Get the currently set vendor-defined DomainParameters builder.
   *
   * @return The currently set vendor-defined DomainParameters builder or null
   *         if none is set.
   * @preconditions
   * @postconditions
   */
  public static VendorDefinedDomainParametersBuilder getVendorDefinedDomainParametersBuilder() {
    return vendorDomainParametersBuilder_ ;
  }

  /**
   * The getInstance method of the Object class uses this method to create
   * an instance of PKCS#11 domain parameters. This method reads the key
   * type attribute and calls the getInstance method of the according sub-class.
   * If the key type is a vendor defined or an unknown it uses the
   * VendorDefinedDomainParametersBuilder set by the application. If no domain
   * parameters could be constructed, this method returns null.
   *
   * @param session The session to use for reading attributes.
   *                This session must have the appropriate rights; i.e.
   *                it must be a user-session, if it is a private object.
   * @param objectHandle The object handle as given from the PKCS#111 module.
   * @return The object representing the PKCS#11 object.
   *         The returned object can be casted to the
   *         according sub-class.
   * @exception TokenException If getting the attributes failed.
   * @preconditions (session <> null)
   * @postconditions (result <> null) 
   */
  public static Object getInstance(Session session, long objectHandle)
      throws TokenException
  {
    if (session == null) {
      throw new NullPointerException("Argument \"session\" must not be null.");
    }
    
    KeyTypeAttribute keyTypeAttribute = new KeyTypeAttribute();
    getAttributeValue(session, objectHandle, keyTypeAttribute);
    
    Long keyType = keyTypeAttribute.getLongValue();
    
    Object newObject;

    if (keyTypeAttribute.isPresent() && (keyType != null)) {
      if (keyType.equals(Key.KeyType.DSA)) {
        newObject = DSAParams.getInstance(session, objectHandle);
      } else if (keyType.equals(Key.KeyType.DH)) {
        newObject = DHParams.getInstance(session, objectHandle);
      } else if (keyType.equals(Key.KeyType.X9_42_DH)) {
        newObject = X942DHParams.getInstance(session, objectHandle);
      } else if ((keyType.longValue() & Key.KeyType.VENDOR_DEFINED.longValue()) != 0L) {
        newObject = getUnknownDomainParameters(session, objectHandle);
      } else {
        newObject = getUnknownDomainParameters(session, objectHandle);
      }
    } else {
      newObject = getUnknownDomainParameters(session, objectHandle);
    }

    return newObject ;
  }

  /**
   * Try to create a domain parameters which has no or an unkown key type 
   * type attribute.
   * This implementation will try to use a vendor defined domain parameters
   * builder, if such has been set. 
   * If this is impossible or fails, it will create just
   * a simple {@link iaik.pkcs.pkcs11.objects.DomainParameters DomainParameters}.
   * 
   * @param session The session to use.
   * @param objectHandle The handle of the object
   * @return A new Object.
   * @throws TokenException If no object could be created.
   * @preconditions (session <> null)
   * @postconditions (result <> null)
   */
  protected static Object getUnknownDomainParameters(Session session, long objectHandle) 
      throws TokenException
  {
    if (session == null) {
      throw new NullPointerException("Argument \"session\" must not be null.");
    }
    
    Object newObject;    
    if (vendorDomainParametersBuilder_ != null) {
      try {
        newObject = vendorDomainParametersBuilder_.build(session, objectHandle);
      } catch (PKCS11Exception ex) {
        // we can just treat it like some unknown type of domain parameters
        newObject = new DomainParameters(session, objectHandle);
      }
    } else {
      // we can just treat it like some unknown type of domain parameters
      newObject = new DomainParameters(session, objectHandle);
    }
    
    return newObject ;
  }
  
  /**
   * Put all attributes of the given object into the attributes table of this
   * object. This method is only static to be able to access invoke the
   * implementation of this method for each class separately (see use in
   * clone()).
   *
   * @param object The object to handle.
   * @preconditions (object <> null)
   * @postconditions
   */
  protected static void putAttributesInTable(DomainParameters object) {
    if (object == null) {
      throw new NullPointerException("Argument \"object\" must not be null.");
    }

    object.attributeTable_.put(Attribute.KEY_TYPE, object.keyType_);
    object.attributeTable_.put(Attribute.LOCAL, object.local_);
  }

  /**
   * Allocates the attribute objects for this class and adds them to the
   * attribute table.
   *
   * @preconditions
   * @postconditions
   */
  protected void allocateAttributes() {
    super.allocateAttributes();

    keyType_ = new KeyTypeAttribute();
    local_ = new BooleanAttribute(Attribute.LOCAL);

    putAttributesInTable(this);
  }

  /**
   * Create a (deep) clone of this object.
   *
   * @return A clone of this object.
   * @preconditions
   * @postconditions (result <> null)
   *                 and (result instanceof DomainParameters)
   *                 and (result.equals(this))
   */
  public java.lang.Object clone() {
    DomainParameters clone = (DomainParameters) super.clone();

    clone.keyType_ = (KeyTypeAttribute) this.keyType_.clone();
    clone.local_ = (BooleanAttribute) this.local_.clone();

    putAttributesInTable(clone); // put all cloned attributes into the new table

    return clone ;
  }

  /**
   * Compares all member variables of this object with the other object.
   * Returns only true, if all are equal in both objects.
   *
   * @param otherObject The other object to compare to.
   * @return True, if other is an instance of this class and all member
   *         variables of both objects are equal. False, otherwise.
   * @preconditions
   * @postconditions
   */
  public boolean equals(java.lang.Object otherObject) {
    boolean equal = false;

    if (otherObject instanceof DomainParameters) {
      DomainParameters other = (DomainParameters) otherObject;
      equal = (this == other)
              || (super.equals(other)
                  && this.keyType_.equals(other.keyType_)
                  && this.local_.equals(other.local_));
    }

    return equal ;
  }

  /**
   * Gets the key type attribute of the PKCS#11 key. Its value must
   * be one of those defined in the KeyType interface or one with an
   * value bigger than KeyType.VENDOR_DEFINED.
   *
   * @return The key type identifier.
   * @preconditions
   * @postconditions (result <> null)
   */
  public LongAttribute getKeyType() {
    return keyType_;
  }

  /**
   * The overriding of this method should ensure that the objects of this class
   * work correctly in a hashtable.
   *
   * @return The hash code of this object.
   * @preconditions
   * @postconditions
   */
  public int hashCode() {
    return keyType_.hashCode()
           ^ local_.hashCode() ;
  }

  /**
   * Check, if this key is a local key; i.e. was generated on the token or
   * created via copy from a different key on the token.
   *
   * @return Its value is true, if the key was created on the token.
   * @preconditions
   * @postconditions (result <> null)
   */
  public BooleanAttribute isLocal() {
    return local_;
  }

  /**
   * Read the values of the attributes of this object from the token.
   *
   * @param session The session handle to use for reading attributes.
   *                This session must have the appropriate rights; i.e.
   *                it must be a user-session, if it is a private object.
   * @exception TokenException If getting the attributes failed.
   * @preconditions (session <> null)
   * @postconditions
   */
  public void readAttributes(Session session)
      throws TokenException
  {
    super.readAttributes(session);

    Object.getAttributeValue(session, objectHandle_, local_);
  }
  
  /**
   * This method returns a string representation of the current object. The
   * output is only for debugging purposes and should not be used for other
   * purposes.
   *
   * @return A string presentation of this object for debugging output.
   * @preconditions
   * @postconditions (result <> null)
   */
  public String toString() {
    StringBuffer buffer = new StringBuffer(256);

    buffer.append(super.toString());

    buffer.append(Constants.NEWLINE);
    buffer.append(Constants.INDENT);
    buffer.append("Key Type: ");
    if (keyType_ != null) {
      buffer.append(keyType_.toString());
    } else {
      buffer.append("<unavailable>");
    }

    buffer.append(Constants.NEWLINE);
    buffer.append(Constants.INDENT);
    buffer.append("Local: ");
    buffer.append(local_.toString());

    return buffer.toString() ;
  }

}
